The disclosure relates generally to vehicle axles. More particularly, the present disclosure relates to a twist beam axle assembly having a reinforcement sleeve used to improve the stress gradient within the twist beam.
Twist beam axle assemblies typically function to transfer the vehicle load through rotatable wheels. The twist beam axle typically interconnects two suspension components such as trailing arms that not only rotatably support the wheels but also function to isolate one wheel of the vehicle from the opposite wheel. The suspension components may include body mounts, wheel spindles, torsion bars, shocks and springs. The twist beam axle may include trailing arms, spring mounts, shock mounts and spindle flanges, among others, to interconnect the various suspension components.
The twist beam axle assembly functions not only to transfer the vehicle load to the ground via the rotatable wheels but also provide desirable riding and handling characteristics as well as proper wheel tow and camber. Previously known twist beam axles typically include U-shaped or V-shaped beams oriented to be relatively rigid in bending but relatively compliant in torsion. These twist beam axles typically include many brackets at each end of the beam to couple the beam to trailing arms or other suspension components. Furthermore, typical twist beam axles provide a torsional stiffness of approximately 350 N-m/degree. While beams having this torsional stiffness have functioned, it may be desirable to provide an increased torsional stiffness of approximately 800-900 N-m/degree. Providing a twist beam axle with a relatively high torsional stiffness may present a challenge due to the local stresses introduced at the interconnection of the twist beam and the trailing arm. Accordingly, it may be beneficial to provide a twist beam axle assembly having a reinforcement sleeve to reduce the magnitude of local stresses found near the interconnection of the beam and the trailing arm.